This PR adds functionalities for middlware (in particular the new OpenPGP middleware) to provide more access to the Msg.
In detail:
The File type now has additional fields: ContentType, Desc and Enc with corresponding `FileOption´ methods to stear those
A new PGPType has been added which can be set as part of the Msg struct using the WithPGPType option method and a SetPGPType setter method
3 PGPTypes have been added: NoPGP, PGPEncrypt and PGPSignature
If a PGPType is set, the msgWriter will produce different MIME headers for the content types
Msg parts received a description field which will be reflected in the Content-Description header of the part. Corresponding Option-, getter- and setter methods have been added: WithPartContentDescription, GetDescription, SetDescription
This PR adds functionalities for middlware (in particular the new OpenPGP middleware) to provide more access to the
Msg.In detail:
Filetype now has additional fields:ContentType,DescandEncwith corresponding `FileOption´ methods to stear thosePGPTypehas been added which can be set as part of theMsgstruct using theWithPGPTypeoption method and aSetPGPTypesetter methodNoPGP,PGPEncryptandPGPSignaturedescriptionfield which will be reflected in theContent-Descriptionheader of the part. Corresponding Option-, getter- and setter methods have been added:WithPartContentDescription,GetDescription,SetDescription